McCreary earned degrees in Composition and Recording Arts from the USC Thornton School of Music, and is a classically trained pianist and self-taught accordionist.[2] He studied under the renowned film score composer Elmer Bernstein during which time he reconstructed and re-orchestrated Bernstein's 1963 score for Kings of the Sun. Their collaboration allowed for the complete score to be available as a soundtrack album for the first time in forty years.[3]

He has also directed and produced several music videos for his brother Brendan McCreary's band, Young Beautiful in a Hurry.[4]

McCreary is married to singer/songwriter Raya Yarbrough, with whom he worked on the music of Battlestar Galactica, Defiance, Da Vinci's Demons, and several other projects.[5][6] They have a daughter together named Sonatine after the musical term sonatina.[7]

In 2003, McCreary worked under primary composer Richard Gibbs on the 3-hour miniseries which served as a pilot for the re-imagined series of Battlestar Galactica. When the show was picked up, Gibbs opted not to devote full-time to the regular series' production, and McCreary became the sole composer. He worked on the series until it reached its conclusion in 2009, scoring over 70 episodes. To date, six Battlestar Galactica soundtrack albums have been released, and have garnered a great deal of critical acclaim[8][9] and commercial success. The soundtracks for season two and three ranked amongst Amazon.com's Top 30 Music Sales on their first days of release.[3]

McCreary composed for Caprica, a prequel series set in the fictional Battlestar Galactica universe. On February 18, 2012, McCreary announced that he would compose the score to the 2-hour pilot movie Battlestar Galactica: Blood and Chrome.

Bear provided the score for the series Human Target (based on the comic book of the same name). The pilot episode and main theme score had been recorded with a full orchestra.[10] The series has the distinction of being one of the few with largest orchestras on television.

The score to the finale of season 1, "Christopher Chance," utilized the largest orchestra ever assembled for episodic television, and he took the opportunity to re-record the main title theme with a new orchestration with this larger ensemble.

In July 2010, he received his first Emmy nomination for the Human Target main title.[11]

In a post on his blog on July 25, 2010, Bear announced the new creative leadership brought in for season 2 had not asked him to return for it, and he would be leaving the series.[12]

McCreary served as orchestral producer for the rock opera Metalocalypse: The Doomstar Requiem airing on Adult Swim on October 27, 2013. This is a continuation of the Metalocalypse universe following the band Dethklok. The music features a 50 piece orchestra. The soundtrack was released on October 29, 2013.[16]

McCreary made an 8-bit rendition of the Dark Void theme, which was, originally, an April fools joke. However, the theme was used for the 8-bit prequel, Dark Void Zero.[19] He composed all the songs in an 8-bit fashion by connecting the wires on an actual NES console and cartridge to create authenticity.